What’s in a name…
Unprecedented warming and the ‘Hockey Stick’ controversy
Current atmospheric change at unprecedented rates
Dutch Elfstedentocht: February 1985
NOAA: climate at a glance
How warm has is gotten? (Ed Hawkins)
https://www.youtube.com/watch?v=jWoCXLuTIkI
Global combined land and ocean-surface temperature was 0.93 of a degree C above the 20th-century average for July 2021. Northern Hemisphere land-surface temperature was the highest ever recorded for July 2021, 1.5°C above average
Physical impacts of climate change are visible
Last decade reveals smallest sea ice extents
The September 2022 average Arctic sea ice extent was tied for the 11th lowest in the satellite record
https://cpb-eu-w2.wpmucdn.com/blogs.reading.ac.uk/dist/3/187/files/2017/06/maparctic_sept_large2_L.gif
The argument for humans as the culprit (pop’n = 7.98 billion)
Haber-Bosch process (1909) and human population
Anthropocene Epoch: http://www.anthropocene.info/great-acceleration.php
Linking socio-economic trends to earth system changes post-1950
Greenhouse gases (ice cores) correlate to warming
Greenhouse gases: Carbon dioxide (CO2)
Global Change and Water are intimately linked
Global Change: Fresh Water Scarcity for 2/3’s of the world
Global Change: Ocean acidification has multiple feedbacks
Global Change: Sea Level Rise
Paris Climate Agreement
- Accord between nation in UN to address climate change
- Goal to keep increase in global temperature below 2 °C
- pursue efforts to limit increase to 1.5
- pursue net zero emissions
- Contributions by country determined by that country
- no emissions targets or dates
- must go beyond current efforts
- framework for transparency
Are targets of the Paris Climate Agreement reachable?
What should we do….
- If CO2 emissions stopped today:
- 50% absorbed by land/water in 30 yrs
- 30% in atmosphere for centuries
- 20% in atmosphere for 1000 yrs
- Future warming is inevitable
- land sinks uncertain
- ocean sinks weakening
- Negative emissions techology?
